Tn 抗原是一种截短的 O -聚糖，在结直肠癌（CRC）中常见。通常在癌细胞中高水平表达。Tn 抗原体积小，结构简单。其在人体内具有非生理性聚糖结构，因此可能被免疫系统识别为异物。 Tn antigen is a truncated O -glycan, that is commonly noticed in colorectal cancer (CRC). It is usually expressed at high levels in cancer cells. Tn antigen is small in size and simple in structure. It has a non-physiological glycan structure in humans, hence it may be identified as foreign by the immune system.